Methods for acquisition and processing of nuclear magnetic resonance signals for determining fluid properties in petroleum reservoirs having more than one fluid phase
US6084408A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 13, 1998 |
| Grant date | Jul 4, 2000 |
| Priority date | — |
| Expiry date | Feb 13, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02A90/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for determining intrinsic transverse relaxation time of a first mobile phase in a porous medium using nuclear magnetic resonance measurement sequences. The sequences are measured at first and second wait times. At least two different interecho spacing times are used for each wait time. The first and second wait time are selected to provide different magnetization recoveries of the first phase, and are selected to be longer than the longitudinal relaxation time of a second mobile phase. For the measurements made at the first interecho spacing time, components of signals in the measurements corresponding to the first phase are separated from components corresponding to the second mobile phase by determining differences between the signals measured at the first and at the second wait times. The step of separating is performed for each of the interecho spacing times. An apparent transverse relaxation time of the first mobile phase is calculated from the separated components for each one of the interecho spacing times. A relationship of the apparent transverse relaxation time with respect to the interecho spacing time is determined, and the intrinsic relaxation time is calculat…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.